Bottom hole intermitter



BOTTOM HOLE INTERMITTER Filed Feb. 7, 1942 ATTORNEY Patented Feb. 6, 1945 l BoTToM HOLE INTERMTTTER t Charles yM. OVLeary, Houston,v Tex. Application February 7, 1942, serial No. 429,938

'z claims.. (o1. 10s-232) N The present'invention relates'generally to that type of pressure controlled and actuated devices,

for intermittently' causing upflowA of liquid ina Well, which are commonly known asbottom hole intermitters, and commonly'used in `oilV wells wherein the formation'pressure is insuilicient to cause outflow of oil under wellpressurafv Intermitters of the above type are usually employed in a manner to permit rise of oil under well pressure Within production tubing to form a head or slug above the intermitter. During this rise of oil, known as the lling period or cycle, the intermitter is effective to prevent the entrance of casing pressure into the tubing, such pressure being provided in the casing from the surface. When the'continued rise of oil? under well pressure results in a head or slug of predetermined weight value, the intermitterl acts to cut off further rise of oil,`and at the same time admit casing pressure into the tubing forfthe purpose ofgblowing to the surface, during the second, or production cycle, the head of oil previ-A ously accumulated during the preceding filling cycle. Many practical considerations are involved in the successful use of a bottom hole intermitter, however, and among them may be mentioned the following. v

Since intermitters of the above character utitected at all times against flowing pressure as lize lcasing pressure provided from the surface and are for Wells having a formation pressure less than that required to continuously flow the same, they are commonly employed with means packing off the casing pressure from the producing formation for preventing back pressure on the latter. It is very important not to prevent, but rather to facilitate, rise of well liquid during the lling cycle.

Furthermore, suchA intermitters -must operate with equal facility in wells of varying pressures, in many of which the formation pressure is very low and the filling cycles are slow, and in many of which the formation pressure is such that it quickly'builds up during each production cyclev sufficient to cause sudden and rapid rise of Lwell liquidduring they initial portion, atleast, of each filling cycle. This' latter condition gives. rise to what is commonly known as a "false filling head and frequently resultsin uttering of the intermitter valves and ineflicient operation.

It is the primary object of thepresent invention to provide lan int'ermitter of the type sei, forth, including a casing pressure ow valve, and a well liquid flow valve,each ofwhich is eiectively held closed while the other is open, which valves are so related that vtheir movements will be positive and unfailing in the presence of varying well or formation pressures.

A further object of the invention is the provision of an intermitterinwhich the valves will be proof against fluttering or uncertainv action, and in which they will be guided byv means prowell as flowing liquid, so that all danger of sticking will be eliminated and a lasting, durable and trouble free life will be assured. 1

With the abovegeneral statement andfobjects in mind, further objects, as well as the resulting advantages of the present invention may be better lunderstood and more thoroughly appreciated from the following description in detail thereof, and by'reference' to the accompanying drawing, illustrating'a practical example oi' the invention, and formingapart'of this'speciiication.` In drawing, l l Figure 1 is a vertical sectional.view'illustrating in amore or less diagrammaticmanner, theinstallation of the bottom hole intermitter in a well. Figure 2 is an enlarged 'detail vertical sectional View through'the intermitter, and,

Figures 3'and 4 are detail vtransverse sectional views taken respectively onllinesw3-3 and 474-,4 ofFigureZ. I i L' Referring now particularly to Figure 1, there is shown an example of vinstallation of the invention in which flow or eduction tubing I0 is illus'- trated Within a well casing II, carrying at its lower end a cylindrical housing I2, forming therein a pressure chamber I3. shown as surrounded by packing I4 within the well casing II, which prevents pressure, fed intol the latter from the surface, from undesirable iniiuence upon the producing formation below the wellcasing. 'f

The housing `I2 is also shown witha pressure I lower end of the eduction tubing I 0.

The lower end of tubing I'I is connected to, and

opens within, the upper section I8 of a cylindrical c asingwhich houses' the intermitter valve, and

whoseV lower ysection I9 depends through the lowerA This housing I2 is of the intermitter casing, and the upper end of the upper section is in communication with the eduction tubing I0. In addition, the upper section I8 has, intermediate its ends, casing pressure ow openings 2| by which it receives casing pressure from within the pressure chamber I3.

Referring to Figure 2, the upper section I3 of the intermitter casing is shown with an internal valve seat ring 22 above the pressure ilow openings 2|. l The lower section I9 is shown with a standing valve 23 in its lower end, which opens to the rise of well liquid. These two sections I8 and I9 are connected at their adjacent ends Iby a valve or partition coupling 24 which separates the gas or pressure chamber 25, within section I8, from the oil or well liquid chamber 26, within section I9, thesechambers being completely iso-I lated from each other.

The valve member within the intermitter casing, consists of an elongated tubular central stem 2-'I which is shiftable lengthwise in an axial bore 2B of the coupling 24. On the upper end of stem 21 is a valve head 29v adapted to seat, in the upper position of the valve member, against valve seat ring 22. On the lower end of said stem is a valve head 39 adapted to seat, in the lower position of the valve member, on a Valve pin 3l which may be supported axially of Athe lower portion of the liquid chamberV 26, on they cage 32 of the standing valve 23.

The valve stem 21 forms therein aliquid flow passage, open at its lower end vinto the liquid chamber 26, through liquid valve 39, only when the latter is unseatedas it is when the valve member is in its upper position. At its upper end, the said passage isopen, through pressure flow'valve' 29, at all times into the `tubing I1, and thus in constant'communication withthe eduction tubing I0. l

The valve stem 21f-'also slides through, and is guided'by, a guide sleeve 33 rising from the coupling 24, the upper end of said sleeve entering a counterbore in the lower face of the pressure iiow Valve 29. A bellows 34 surroundsslee've 33, with its upper end sealed in connection with pressure flow valve 29,and its lower end similarly sealed in connection with the upper rsurface of coupling 24. f

Around the lower portion of the stem 21 of the valve member, a second bellows 35, ofsubstantially less eiective area than the bellows 34, is disposed with its upper end-in sealed connection with the lower surface of coupling 24, and its lower end in similarly sealed connection with the liquid flow valve 3D. Externally of the latterY bellows 35, a surrounding coil spring 36 is disposed under compression between coupling 24 and the liquid ow valve 39, tending to press the valve member downwardly at alltimes from its upper liquid rising position shown in Figure 2, to its lower pressurefowing position wherein the rise of liquid is cut o.

The coupling .24 is shown with gas or pressure ports 31 in its wall in open communication with the pressure chamber I3, from which ports feedA channels 38 extend upwardly and open at their upper ends into the lower end of bellows 34, so as to maintain within both bellows 34 and 3 5, the existing casing pressure at all times. It is to ble noted, however, this arrangement forms no part of the pressure ilow passage or line in operation.

It will also be noted that the eiective area of bellows 34, while greater than that-of bellows 35, is somewhat less than t'he effective area of the seat 22 of the pressure ilow Va1ve-29. Onv the chamber through the Valve stem 2l and tubing y -I'I, into the eduction Vtubing I0.

l At this time casing pressure is cut off from the tubing I9, by reason of the fact that pressure flow valve 29 is held on its seat 22 by pressure upwardly therey against externally, and internally of bellows 34.

Such pressureovercomes the pressure within the smaller lower bellows 35 and that exerted by the spring 36, and is effective to tightly hold the pressure ilow'valvefin closedposition. Since the effective area of bellows 34 is ,somewhat less than the effective area of valve seat 22 it is apparent that when valve 29 -is seated the pressure in chamber 25, becomes eiective to create an upward closing or seating force on valve 29 which holds it moretightly against its seat.A When valve 29 is open Vhowever the pressure in chamber 25`no longer tends to create an yupward closing force.

When, during the filling cycle, a liquid head or slug builds up in the eduction tubing I0, and reaches a weight value o n the upper effective area of valve 29, sufficient to overcome the previously preponderant casing pressure tending to hold thel valve closed as above, it will, with the help of the spring 36 and the pressure within the smaller, lower bellows vagainst the liquid valve 3U, force the valve member downwardly, thus unseating the pressure flow valve 29 and seatingy the liquid flow valve 30.

With the valve member in lower position, presn sure flow valve 29 is-open, permitting the flowy of casing ypressure into the tubing I0 through the restricted openings 2|, and thus, vwith valve 3D closed and cutting 01T further rise of well liqui-d,lthe head or slug of oil, previously accumulated, will be caused to upflow in the tubing to discharge. During this period,l known as the production cycle, after the slug reaches'the sur- Viace and discharges, there is a pressure drop in thev tubingr above the intermitter and also in.

chamb`er'25, due to the restrictedfiow of pressure through openings 2I. When this drop occurs, the constant vlpressure within bellows 3'4, acting against the preponderantly greater lower area of valve 29, overcomes pressure in the lower, smaller bellows 35 acting againstthe liquid valve 39, plus the pressure of springV 36, to thus again shift the valve member upwardly to seat the pressure flow valve 29 and unseat the liquid ow valve 39, for the next lling cycle.

Should considerable pressure build-up below the intermitter and within liquid chamber 26 during the blow down or production cycle, it will act during such cycle merely as an additional means maintaining the liquid valve 36in seated position, since the eiective area of ythe lower bellows 35 is no greater, and is preferably less, than the effective seatingv area of said valve. When vthe liquid ilow valve 30 is unseated at the start of afilling cycle such liquid pressure as above, cannot have theeffect of closing or seating the valve, since thelatter will tend to be held upwardly by theup-rush of the liquid passand decrease the height or head of oil formedin aangaan 3.

the tubing Ht during 'each llingA cycle. This same result may, ofcourse, be vobtaimd bythe regulation of the casing `pressure which, in op-- eration flows onlythroughl pressure chamber 25' and' past valve 29'. Since. the bellows feed channels 38" form no part of the pressure 'flow passage, there is no tendency"toward` carrying foreign matter into the bellows and the -guiding means for the valve member. Thus the bellows act to protect the guiding portions of the valve member at all times against foreign matter in the gas as well as the oil.

Having thus fully disclosed the present invention, what is claimed is: 1

l. In a bottom hole intermitter, a casing having therein a pressure iluid'flow passage, a valve member movable in the casing to close Said passage in one position thereof and open said passage in another position thereof for the upow of pressure fluid, said valve member having a liquid flow passage therein for the upow of liquid ensitioned to cooperate with said valve member for vopening its said liquid flow passage in its rst mentioned position and closing said liquid ow passage in its last mentioned position, said valve member being exposed externally thereof within the pressure'fluid flow passage, means forming a pressure chamber internally of said valve member, and means for supplying pressure fluid to said internal chamber of the valve member independent of, and isolated from, the pressure fluid and liquid ow passages.

2. In a bottom hole intermitter, a casing having therein a pressure fluid flow passage, a valve member movable in the casing to close said passage in one position thereof and open said passage in another position thereof for the upflow of pressure iluid, said valve member being of unitary nature and having a liquid flow\ passage therein for the upflow of liquid entering the lower portion of the casing, means positioned to c0- operate with said valve member for opening its said liquid flow passage in its said first mentioned positionand closing said liquid flow passage`in its last mentioned position, said valve member being exposed externally thereof to the influence of pressure fluid in the pressure'flow passage, means forming a pressure chamber internally of said valve member, and means for supplying pressure fluid to said internal chamber of the valve member independent of, and isolated from, the pressure uid and liquid flow passages.

3. A bottom hole intermitter, including a casing having therein a pressure chamber and a liquid chamber, a valve member, means controlled by said valve member and movable in said chambers to alternately open the rliquid chamber for upflow of liquid therefrom and close the pressure chamber in one position thereof and to open the pressure chamber for upow of presthe inlet,` and 'also having a liquid chamber pre;V vided with a liquid inlet, a unitaryvalve member shiftable in said casing and having a liquid flow channel, means controlled by said valve member to alternately open the liquid flowchannel and close the pressure flow passage inone position thereof, for the upfl'ow of` liquid` and to Afopen the pressure fiovv7 passage and close the liquid flow* channel in the other position thereof, for the upow of pressure fluid, spring means tending to force said member to pressure iiow position, and

means isolated from said liquid and pressure flow passages for admitting'pressure intosaid valve member tending to force the said member to liquid flow position.

5. In a bottom hole intermitter, a casing having a pressure chamber provided with a restricted pressure inlet and a pressure flow passage above said inlet, land also having `a liquid chamber provided With a liquid inlet, a unitary valve member shiftable in said casing and having a liquid flow passage, means controlled by said valve member to alternately open the liquid flow channel and close the pressure flow passage in one position thereof, for the upflow of liquid and to open the pressure flow passage and close the liquid ow channel in lthe other position thereof, for

the upflow of pressure fluid, said member being exposed externally thereof to pressure in the pressure chamber, means in sealed 4connection with said valve member forming an internal pressure chamber Within the member, and means for- 5 heads respectively engageable with said seats in sure fluid therefrom and close the liquid chamthe upper and lower positions of said valve member, said valve member having a liquid passage vand said valve heads being exposed to the influence of pressure in said chambers and relatively` positioned to alternately open upiiow of liquid and close upflow of pressure inthe upper position of the valve-member, and to open upow of pressure fluid and close upow of liquid in the lower portion of the valve member, flexible means in sealed connection with the valve heads and the'casing partition and forming an internal pressure chamber within the valve member, and means in said partition for admitting pressure into said internal chamber independent of, and

isolated from, the pressure and liquid chambers of the casing.

'7. A bottom hole intermitter, including a casforming a liquid flow passage, and also having f upper and lower valve heads arranged respectively to moveAoff of the seat of the liquid chamber and onto the seat of the pressure chamber in one position of the valve member for the upchamber within Vthe'valve xrmber` around Yits stem, said partition having externally opening ports and channels from said ports opening into the'said internal pressure `chamber of the Valve member, for supplying pressure rthereto independent of, and isolated from the pressure chambers of the casing. v

lCHARLES OLEARY. 

